Different types of brushes are utilized in different industries and for different applications. Commercial brushes, such as those for use in connection with street sweepers, car washes, in-plant sweepers, airports, etc., are highly customized for its specific application. Typically, due to the varied developments over the years of commercial brushes, brushes used in one industry cannot easily be adapted for use in another industry. Different manufacturers use different machinery to produce the brushes. Therefore, purchaser of a brush for a particular industry or application has limited sources. And since a manufacturer is unable to provide brushes to different industries, it cannot readily benefit from the reduced cost savings resulting from mass production.
Even within an industry, such as street sweeping, different brushes are used. A street sweeper typically has a reusable cylindrical core with replaceable radiating brush elements attached to the vehicle and a replaceable gutter broom with downward extending brush elements on each side of the vehicle. While the core with brush elements and gutter broom are normally produced by the same manufacturer, the processes for their manufacturing are very different and require separate sets of machinery to produce.
Different industries also use a reusable cylindrical core similar to those used in street sweepers. For example, airport brush cassettes, car washes, etc. Currently, such cores are made out of metal. On the outer surface of the core, along the longitudinal axis, is a plurality of U-shape channels for receiving strips of bristles that are made out of metal or plastics. The mixed use of a metal core with either metal or plastic bristles does not allow such brush to be easily recyclable. There are two typical prior art methods of producing these U-shape channels on the core.
One prior art method is by extrusion, wherein the combined U-shape channels and core are extruded. See U.S. Pat. No. 6,817,055 to Hans Ekholm. There are many disadvantages and limitations to this prior art process: (1) dies used for the extrusion process is limited in size so that only certain maximum diameters can be produced; (2) extruded sections are extremely heavy since the material is thick and is impossible to reduce the mass by inserting cavities; (3) extremely expensive tooling costs, and in most cases, restricted to shapes and sizes for a particular industry or market; (4) extruded metal tends to cure and bend while cooling, requiring the need to rework for dynamic balancing for high speed usage; (5) extruded U-shape channels must align with the axial length of the core; and (6) difficult, if not impossible, to provide different patterns (such as helix, or non-linear) on the core.
Another prior art method is by welding a U-shape channel onto a core. Each U-shape channel is formed by roll forming a flat metal sheet, then pinched. There are many disadvantages and limitations to this prior art process: (1) dies used for the roll forming of the U-shape channel is limited in size so that only certain maximum diameters can be produced; (2) each U-shape channel has a maximum width before it will not make sufficient contact with the core; (3) extremely expensive tooling costs, and in most cases, restricted to shapes and sizes for a particular industry or market; (4) if non-corrosive material is needed, expensive and difficult to work with when welding; (5) requires the use of a large and expensive spot welding machine to weld the U-shape channels to the core; (6) axial length of the core is limited to the size of the spot welding machine; (7) skilled and time intensive labor required to weld the seams of the U-shape channels every few inches across the entire length of the core to prevent the U-shape channels from pulling off at the seam; (8) U-shape channels can only be mounted along the axial length of the core; and (9) difficult, if not impossible, to provide different patterns (such as helix or non-linear) on the core.
Currently the most common process that allows different patterns on brushes is a staple set machine that staples bristles directly to a non-metallic core. There are many disadvantages and limitations to a staple set brush: (1) the core cannot be efficiently reused since the metal staples must first be removed; (2) core must be of sufficient thickness to support the stapled bristles; (3) the use of a thick core is costly; and (4) the use of a thick core is heavy, difficult to manipulate and increases shipping costs.
Therefore, there is a need for an improved brush system that is modular to allow production of customizable brush that can be used in different industries and applications with ease, at a low cost and also easily recyclable.